Tools used in the machining of metals may be exposed to conditions that wear on the tool. Over time, the wear on the tool may alter the tool surface, and may decrease the efficiency of the tool or render the tool unsuitable for use. A variety of coatings have been applied to tools in an effort to increase the usable lifespan of the tool. An example of such a coating is a titanium nitride coating. Titanium nitride coatings reduce wear and retain cutting edges.